The present invention relates to a blood purifying filter and a blood purifying apparatus including the blood purifying filter, which are configured to separate plasma from blood of a patient using a plasma separation filter, remove hepatic toxins from the separated plasma using adsorbents, such as activated charcoal or anion exchange resin, and simultaneously perform hemodialysis which removes water-soluble toxins and uremic toxins from blood.
When a liver function is damaged, the toxins and waste products to be removed from a body by the liver are accumulated in the body. If the liver transplant is not performed in a timely manner, the blood purification treatment such as dialysis, filtration or adsorption in which blood is circulated out of body must be performed to remove those toxic substances.
Liver performs many functions such as a metabolic function of treating various nutrients existing in our body, a function to store nutrients required by our body, a synthesizing function to synthesize gall juice and albumin, and a function to detoxify various toxins brought into our body such as alcohol or drug. Accordingly, when a liver is damaged, the substances such as ammonia and bilirubin to be removed from a body by the hepatic metabolism are accumulated in the body. The accumulation causes complications such as jaundice, hepatic encephalopathy, and multiple organ failure.
In case of acute liver failure, a liver transplant is regarded as the decisive cure. However, as shown by the liver transplant data published by OPTN/SRTR Annual Report in 2011, only 36% of the patients waiting for the liver transplant actually receive the treatment. In addition, according to the organ transplantation report from Korean Network for Organ Sharing (KONOS), only 22% of the patients on the waiting list receive the liver transplant. It is because the donor organs are substantially short as compared with the required numbers of liver transplant. Therefore, an artificial liver treatment is required for liver failure patients to serve the function until a liver transplant or self-recovery.
Artificial liver apparatuses currently in clinical use are limited to MARS of Gambro Inc and Prometheus of FMC. MARS removes hepatic toxins from blood by adding a plasma protein called albumin in dialysis fluid. Since albumin is expensive, MARS comes to a costly treatment. Prometheus has such configuration that plasma is separated from blood to be filtered through ion-exchange resin adsorbent for removal of toxins existing in the plasma and then hemodialysis is performed after the plasma separation and adsorption. Accordingly, Prometheus apparatus has a complicated system including a plasma separation filter, two adsorption filters, and hemodialysis process, giving rise to a high treatment cost like MARS.
In order to solve such limitations of typical artificial liver systems, Korean Patent No. 1071402 entitled “Apparatus for Purifying Blood” discloses an apparatus that is configured to remove toxins from plasma without using expensive albumin and integrate plasma separation and absorption processes into a single filter. By implementing plasma separation and adsorption processes in a single filter, the entire artificial liver system is simplified from the typical artificial liver apparatuses. However, the system still requires additional hemofiltration or hemodialysis process. That is, in a case of a patient who needs intensive blood purifying treatment for liver failure, the removal of water-soluble toxins by hemodialysis or hemofiltration is as important as the removal of liver toxins or protein-bound toxins through adsorption.
As a method of overcoming such limitations, an apparatus which further simplifies the blood purification system by implementing plasma separation, plasma adsorption and hemodialysis in a single filter is also disclosed in Korean Patent Publication No. 2014-0077804. The plasma is separated across the plasma separation membrane by the operation of plasma pump, and the separated plasma passes through a plasma flow hole and a plasma flow section which is filled with adsorbents. In other words, plasma is configured to pass through the plasma separation membrane, the plasma flow hole and the plasma flow section filled with adsorbents, all of which act as resistance to plasma flow. Accordingly, despite the operation of the plasma pump, it is substantially limited to attain plasma flow rates required for the treatment.